1. Field of The Invention
This invention relates to wireless communications and, more particularly, to a system for converting an existing subscriber of a first wireless communications system to a second wireless communications system.
2. Description of Related Art
FIG. 1 depicts a schematic diagram of a wireless communications system 10 which provide wireless communications service to a number of wireless units (e.g., wireless units 12a-c) that are situated within geographic regions 14 and 16. A Mobile Switching Center (e.g. MSCs 20 and 24) is responsible for, among other things, establishing and maintaining calls between the wireless units and calls between a wireless unit and a wireline unit (e.g., wireline unit 25). As such, the MSC interconnects the wireless units within its geographic region with a public switched telephone network (PSTN) 28. The geographic area serviced by the MSC is divided into spatially distinct areas called xe2x80x9ccells.xe2x80x9d As depicted in FIG. 1, each cell is schematically represented by one hexagon in a honeycomb pattern; in practice, however, each cell has an irregular shape that depends on the topography of the terrain surrounding the cell. Typically, each cell contains a base station (e.g. base stations 22a-e and 26a-e), which comprises the radios and antennas that the base station uses to communicate with the wireless units in that cell. The base stations also comprise the transmission equipment that the base station uses to communicate with the MSC in the geographic area. For example, MSC 20 is connected to the base stations 22a-e in the geographic area 14, and an MSC 24 is connected to the base stations 26a-e in the geographic region 16. Within a geographic region, the MSC switches calls between base stations in real time as the wireless unit moves between cells, referred to as call handoff.
The MSCs 20 and 24 use a signaling network 32, which enables the exchange of information about the wireless units within the respective geographic areas 14 and 16, for location validation and call delivery to wireless units which are roaming in other geographic areas. For example, a wireless unit 12a is roaming when the wireless unit 12a leaves the geographic area 14 of the MSC 20 to which it was originally assigned (e.g. home MSC). To ensure that a roaming wireless unit can receive a call, the roaming wireless unit 12a registers with the MSC 24 in which it presently resides (e.g., the visitor MSC) by notifying the visitor MSC 24 of its presence. Once a roaming wireless unit 12a is identified by a visitor MSC 24, the visitor MSC 24 sends a registration request to the home MSC 20 over the signaling network 32, and the home MSC 20 updates a database 34, referred to as the home location register (HLR), with the identification of the visitor MSC 24, thereby providing the location of the roaming wireless unit 12a to the home MSC 20.
The HLR 34 contains subscriber information and location information for all wireless units which reside in the geographic area 14 of the MSC 20. The HLR 34 includes a mobile identification number (MIN) or International Mobile Subscriber Identification Number (IMSI), the mobile directory number (MDN), and/or an electronic serial number (ESN) for each of the wireless units. An authentication center (AC) 35 authenticates a wireless unit by using the MIN/IMSI and ESN of the wireless unit and data stored in the HLR 34. After a roaming wireless unit is authenticated, the home MSC 20 provides to the visitor MSC 24 a customer profile which indicates the features available to the roaming wireless unit, such as call waiting, caller id, call forwarding, three-way calling, and international dialing access. Upon receiving the customer profile, the visitor MSC 24 updates a database 36, referred to as the visitor location register (VLR), to provide the same features as the home MSC 20. The HLR, VLR and/or the AC can be co-located at the MSC or remotely accessed.
There are different radio standards for wireless cellular communications systems which determine how a wireless unit communicates within the wireless communications system 10 or variations of the wireless architecture thereof. The different radio standards include wireless communications systems using code division multiple access (CDMA), Advanced Mobile Phone System (AMPS), Global System Mobile (GSM), North American time division multiple access (North American TDMA), Total Access Cellular System (TACS), European Total Access Cellular System (ETACS) and others. These wireless cellular communications systems have evolved from first generation analog systems based on frequency modulated (FM) voice technology, such as AMPS, to second generation digital systems, such as wireless cellular communications systems based on CDMA, TDMA and GSM. The first generation systems had limited capacity. The second generation systems provide increased capacity and service capabilities. For example, the second generation systems are being networked to provide seamless roaming, call delivery and handoff services on a national and international basis. Third generation wireless cellular systems are evolving from second generation systems which provide improved access to voice and data networks. Certain radio standards, such as CDMA, are recognized as being well suited for implementing third generation wireless systems.
In this environment of evolving wireless communications systems, wireless service providers may change or convert the service provider""s wireless communications system to a different standard, such as CDMA, which more readily supports implementing third generation wireless systems. To do so, the service provider typically asks the existing subscribers to go to a store or outlet to select a new wireless unit for the new wireless communications system. After selecting the wireless unit, the existing subscriber calls a customer registration service 38 using the new wireless unit to activate the new wireless unit and get a phone number (DN) and/or a new IMSI. A human operator at the customer service 38 asks for subscriber information, such as billing information and features or services desired by the existing subscriber. The operator inputs the new subscriber information into a database in the customer service 38, and the customer service 38 assigns a DN and/or new IMSI to the new wireless unit. The new wireless unit already has the ESN and a dummy International Mobile Subscriber Identification number (IMSI). An over the air service provisioning process (OTASP) programs the DN and/or the IMSI into the new wireless unit using an over the air function (OTAF) 40 which allows the IMSI and/or DN to be programmed into the new wireless unit. The activation process provides the new subscriber information at the customer service 38, including the DN, IMSI, billing information and/or services, to the HLR 34 of the home MSC 20. Once the home MSC 20 has the subscriber information or customer profile in its HLR 34, the new wireless unit is activated.
The OTASP process was designed for new subscribers, and the process takes about 20-25 minutes to activate a wireless subscription. If the service provider informs all existing subscribers to exchange an existing handset for a new handset to support the new radio standard, it is difficult to predict the numbers of operators required to handle the conversion of the existing subscribers from the previous wireless communications system to the new wireless communications system using the new radio standard. As such, subscribers may be required to wait excessive periods of time for an operator to answer the call and process the activation procedure for the subscriber""s new wireless unit. Moreover, during the conversion period, the service provider will be exposed to increased costs, for example due to increased staffing and training, and may dissatisfy existing subscribers. Thus, a conversion system is required to reduce the problems associated with converting an existing subscriber for a first wireless communications system to a second wireless communications system.
The present invention involves a subscriber conversion system which determines at least one code for an existing subscriber of a first wireless communications system to be converted to a second wireless communications system. When the existing subscriber obtains a wireless unit to be used in the second wireless communications system, the conversion system uses the at least one code provided to the existing subscriber to link existing subscriber information from the first wireless communications system to information associated with wireless unit for the second communications system, thereby improving the efficiency of the conversion process. For example, if a service provider wishes to convert from GSM to CDMA, the service provider can provide a secret code and an identification number, such as a directory number (DN), as the codes to the existing GSM subscriber. The subscriber obtains a CDMA wireless unit and commences an activation process to activate the CDMA wireless unit. As part of the activation process, the subscriber provides the secret code and the identification number to the conversion system. The conversion system determines if the secret code and the identification number correspond to the secret code and identification number provided to an existing GSM subscriber. If so, information which is characteristic of the CDMA wireless unit, such as the ESN, DN and/or IMSI, is associated with at least a portion of existing GSM subscriber information, such as billing information and/or features or services. As such, the conversion system uses existing subscriber information to reduce the time required to convert the existing subscriber to the wireless communications system based on the second radio standard.